What do you use to build your upper?

[bob4432]

As title states, what do you use to build your upper? Clamshell, Reaction Rod or Magpul BEV Block? Note that the upper will have to be heated up pretty good as I will be using a Bravo Company Lower and they state they are tight to begin with (on purpose) and the one I have is in fact is very tight, as even a upper w/ a standard m4 extension would only go in 1/2 way before heat was applied, so if that is a consideration, please let me know.

[Recondo]

After doing research I went with the Bev block. My reasoning was added strength of using the bolt carrier body with it and no stress on the indexing pin. So far used it to change a muzzle device and no problem. Works as advertised.

[A5BLASTER]

Bev block, unless I'm taking a barrel off then I use a clamshell so I can put a piece of broom handle in the upper and give the barrel extension a few pops and get it moving out.

[grayfox]

I use a clamshell, the delta eng series I think? anyway, with BCM uppers, heat the upper in the oven to 175 for 15 min and place the barrel in freezer, watch out for condensation (I didn't see any but some folks have), then they slip together nicely. Everything else can be done in the clam in the vice. use counter-force to prevent over torqueing. I've built probably 10 uppers in the past few years, no problems at all. For any muzzle devices use jam nuts and locktite so you don't have to clock them.

eta: o and some anti-seize on a few barrel nut threads.

[bob4432]

I use a clamshell, the delta eng series I think? anyway, with BCM uppers, heat the upper in the oven to 175 for 15 min and place the barrel in freezer, watch out for condensation (I didn't see any but some folks have), then they slip together nicely. Everything else can be done in the clam in the vice. use counter-force to prevent over torqueing. I've built probably 10 uppers in the past few years, no problems at all. For any muzzle devices use jam nuts and locktite so you don't have to clock them.

eta: o and some anti-seize on a few barrel nut threads.

Thanks for the suggestion, sounds good. Out of curiosity, since I eat out of this oven, the BCM uppers have, I believe teflon on the inside - maybe not teflon but there is a coating on the inside of the upper in addition to the anodization - you know of any issue of any type of off-gassing (not sure if that is the correct term, but I think you know what I am talking about).

Thanks.

[grayfox]

I haven't noticed any, 'course we eat of our ovens too.
Remember that teflon (the generic term is ptfe IIRC) used to be the non-stick that coated every pot n pan you could own...
If it is teflon, that won't cause any troubles at 175, and for only 15 minutes. Now heat it up to -- i don't know -- 500 or more, or something then you got gasses coming out!!! (but I forget the actual temp, might even be hotter than 500..... old brain cells lol).
Temperature control is the thing here.

175 is about as warm as you would heat your left over pot roast for eating on day 2...

[bob4432]

I haven't noticed any, 'course we eat of our ovens too.
Remember that teflon (the generic term is ptfe IIRC) used to be the non-stick that coated every pot n pan you could own...
If it is teflon, that won't cause any troubles at 175, and for only 15 minutes. Now heat it up to -- i don't know -- 500 or more, or something then you got gasses coming out!!! (but I forget the actual temp, might even be hotter than 500..... old brain cells lol).
Temperature control is the thing here.

175 is about as warm as you would heat your left over pot roast for eating on day 2...

Thanks, I will see how low my oven will go.

[Klem]

Can't remember the last time I used a clamshell. They also don't fit some non-MILSPEC uppers.

Working on the premise that we isolate torque as close to the spot we are working on I use a Reaction Rod for barrel nuts and a barrel vise or clamps for muzzle devices. I prefer not to load up the aluminium upper. If the upper is a tight fit then clamp the barrel vertically, grease the mating surfaces and use a rubber hammer to tap the upper on. 'Slow and steady wins the race'.

[maxxmojo]

I used a reaction rod, forget where I got it from. Used a Lilja barrel and an Aero cerakoted upper. The fit was pretty tight, enough where I couldn't get the barrel in all the way by hand. What I ended up doing was sticking the barrel in the freezer, then after a half hour or so I took a hair dryer to the upper to warm it up. Once it got pretty warm I pulled the barrel out of the freezer and it went into the upper like butter. I held both parts together until the temperatures normalized enough to where the barrel would stay in on it's own. I didn't torque the barrel nut down until the next day, had to use the vise at work for the reaction rod.

[SDW]

Note that the upper will have to be heated up pretty good as I will be using a Bravo Company Lower and they state they are tight to begin with (on purpose) and the one I have is in face very tight, as even a upper w/ a standard m4 extension would only go in 1/2 way before heat was applied, so if that is a consideration, please let me know.

The BCM lower is "tight"?? How so?

[Swampfox]

I use the Bev block

[bob4432]

The BCM lower is "tight"?? How so?

They are manf that way, and they do deliver. Can't get any barrel in more than 1/4-3/8 by hand. Heat gun is necessary unless you are the Hulk. It is listed on their site, so it is on purpose, not a surprise. Have wondered if mixing their tightness with a coated extension would be high enough to deform the upper enough to cause accuracy issues, but judging by the amount they sell, seems to not be an issue.

[SDW]

I think you might have meant to say Upper. The extension doesn't touch the Lower. That's what confused me. I'm not sure the lower is actually relevant:

I will be using a Bravo Company Lower and they state they are tight to begin with (on purpose)

FWIW though, I have removed a BCM stainless RECCE barrel from its BCM upper and reinstalled it, when I switched to free-float. Yes it's a very tight fit and took a little effort, but I didn't need to apply any heat; just yanked hard to get it out and maybe employed a plastic mallet to get it back in.

BTW, I used my plastic clam-shell upper holder.

[Kswhitetails]

Use the RR myself, never wanted anything more. I also use a bagwell block I got from Brownels, works like a champ.

[Jakegsxr11]

Reaction rod... Works well.

[JohnXDm]

Put your barrel in the freezer and use a hand held hair dryer to heat your upper. Cold barrel will slide right in. I like to use the clamshell to keep the lower out of the mix.

[bob4432]

I do have a heat gun, maybe this is a dumb question but I will ask it anyway - While I will put the barrel in the freezer, does it matter if I use a heat gun or a hair dryer? Just wondering if the heat gun would create too much heat? Or wil the heat gun heat up the upper too quick? Just wondering if this is a non issue or something I should be concerned with?

Thanks and Happy New Year (in a couple days )

FWIW, I have a BEV on the way and a clamshell here already, so I should be g2g. Figure the BEV would be the way to go since that way the most amount of torque will be on the barrel. Then I will make some barrel clamps to put in the vise for other items, but I do not think I will really need them, other than to actually hold the upper/barrel assembly. Reason being is that I plan on using a clamp adjustable gas block and a A1 style or some type of brake that will all be applied w/ the proper torque amounts per manf along w/ loctite for the gas block (torque amount for the allen screws) and using loctite, just a bit over hand tightening for the brake w/ the proper shims to time it or just a single shim if I get a A1 style flash suppressor. Reason I am choosing a A1 style is that way the there is no 'floor' on the hider thus making sure gas escapes all around the path at approximately the same rate, at least as close as possible. Or I may just use a thread protector and loctite that on the end as I try to get recoil down as far I can - plan on using a lightweight carrier, agjustable gas block, change the single tungsten weight in the buffer to an Al one.

Anything else you guys may have a suggestion, please suggest away as I am always open to suggestions. FWIW, this will be going on a 16" Group Buy "Monster" barrel. So I am trying to go legal shortest barrel (16") with the least amount of recoil. I think I have covered all the basis, but multiple minds are better than a single one. This will not be a 'fighting' rifle, more of one to get me on the road to accurate shooting, so the minimum amount of gas to operate reliably shooting at paper or steel is what I am looking for, I have other rifles that would be use in case of a 'situation' where reliability is of utmost importance.

Thanks,
Bob

[Rangerofthenorth]

I use the Bev block secured in the upper by the BCG minus the bolt.

[JohnXDm]

I've always used a hair dryer. I would be concerned that a heat gun could cause damage. You're only working with aluminum and it doesn't take much heat. Don't forget to lubricate the barrel extension and the receiver threads. Too much heat will bake off any lubrication and the remaining residue will just cause more resistance while trying to seat your barrel. I have a Bev and clamshell, can't see any reason for a barrel clamp.

I don't like clamp on gas blocks. I always dimple my barrel so that the set screws have a pocket. That stops any chance of gas block movement and ensures proper gas block alignment. My Grendel has an 11 inch barrel, recoil has not been an issue.

[SDW]

A heat gun will produce as much or as little heating as you need. Just depends on the setting (Low vs. High), how far away you hold it from your work, and how long you apply it.

I think the hair drier is good for getting the piece warm but can't make it "hot" to the touch. This might be good enough. Worth trying. Especially since it may not be absolutely necessary to use heat anyway. As I said above, I didn't when pulled my BCM upper apart---just didn't occur to me to use heat. Duh. I admit that it might have made the job easier though. I was trying to remember exactly why the heck I did that anyway. It was to remove the delta ring assembly from the barrel. That has to come off the back of the barrel. My BCM upper came configured for a drop-in HG. I ran that for a while and then decided to install a Troy Alpha FF HG.